This invention relates generally to lifting and stabilizing apparatuses for vertical auger type bag filling machines, and particularly to a mechanism employing opposing Z-belts.
Lifting and stabilizing mechanisms for automated bag filling equipment, alternately referred to as bag elevator assemblies, are know to the art. Existing lifting and stabilizing mechanisms usually comprise vertical tracks on which carriages travel, the tracks having beveled edges which engage grooved guide wheels on the carriage, or vice versa. The carriages are generally lifted and lowered using a combination of one or more drive gears and chains, servos, or dual acting power cylinders. A representative example of such a mechanism as described above may be seen in U.S. Pat. No. 4,944,334 and its related applications.
These lifting and stabilizing mechanisms are used to control the raising and lowering of bag handling mechanisms, including bag gripping and hanging mechanisms for mounting and holding a bag on a fill spout, and mechanisms for moving that bag relative to a fill tube or fill spout during filling by a filling machine such as a vertical auger bag filler. These lifting and stabilizing mechanisms may also be utilized to carry bag tamping or settling mechanisms, net weigh scales, and additional equipment or controls.
In order to ensure proper vertical alignment and uniform horizontal orientation, the configuration of conventional lifting and stabilizing mechanisms generally require very heavy and bulky assemblies. The increase in size and weight of the mechanisms requires proportionately higher capacity drives in order to controllably lift and lower the mechanisms at the speeds required by automated fill systems, and proportionately larger areas in which the machines are placed. In a system for filling fifteen 100 lbs. bags per minute with a powdered product, for example, the lifting and stabilizing mechanism might account for ten to twenty times the weight of the filled bag. Consequently, the mechanism is far more difficult to tune, requires heavier duty and more expensive components to endure prolonged usage, requires more complicated controls and regulating mechanisms to ensure accuracy and uniformity over extended periods, and generally consume more energy and are less efficient than lighter and smaller mechanisms. The size of these mechanisms can also affect the ability to integrate other devices, such as bag infeed or hanging mechanisms, release and conveyor assemblies, weigh scales, vacuum systems or de-aeration mechanisms, and safety or control devices.